Motiva is a state owned limited company from Finland offering energy efficiency analysis and energy audit for companies. Motiva also developed audit guidelines and models, and engages in training and authorisation of the energy auditors.

In their energy audit reports, they always include a Sankey diagram in the very first chapter. Here is an example:

Other consulting companies, such as Pöyry (not sure how to pronounce this) haven taken on their approach and are also producing Motiva style Sankey

Both Sankey diagrams designed in PowerPoint. Not bad at all, but probably quite a time-consuming task.